1. Field of the Invention
This invention concerns a new type of tipping device controlling the tipping of a body on the chassis which carries it. It deals, more particularly, although not exclusively, with instances where the carrying chassis is a truck, trailer or semi-trailer.
2. Description of the Prior Art
Tipping devices mounted between the carrying chassis of a truck and the lower part of a tipping body are known already, in particular French Pat. No. 1 453 849.
We know that such a device must first satisfy the clearance space requirements. It has to be possible to mount it on an existing truck without the necessity of modifying the chassis. It has to fit into a minimum amount of height, under the tray or floor of a standard tipping body or container. As the device rests on the chassis of the truck at one end and the under part of the tipping body at the other, neither of these standard units should need elaborate reinforcing due to too much force being used in its operation. Because of these considerations, the one or more principal tipping thrustors occupy a position only slightly inclined towards the horizontal when the body rests horizontally on the truck. Because of this, the one or more principal thrustors operate with a minimum amount of leverage at the start of the initial lift at the time when the effort required of the principal thrustor is at its maximum. It is, therefore, this particular moment of operation which is taken into consideration when calculating what the size of the principal thrustor should be, as well as the various parts and joints which bear the load pressure exerted. Consideration must be given to the weight and cost of these various elements. The advantage of reducing the thrust of the principal thrustor is easily understood, this thrust being needed at the start of the cycle, i.e. the moment at which the body starts to lift.